Some methods have already been known for the synthesis of dihydroacetinidiolide which is one component of the queen recognizing pheromone of red imported fire ant (Solenopsis invicta Buren). One of them starts from a methyl ester of (-)-azafrin which is a carotenoid (W. Eschenmoser, P. Uebelhart and C. H. Engster, Helv. Chim. Acta., 65, 353 (1982)). The starting material of this method is a naturally occurring substance and is not readily available. Furthermore, only the (-)-isomer can be obtained with a low optical purity.
Another known method starts from (4R,6R)-4-hydroxy-2,2,6-trimethylcyclohexanone obtained via asymmetric reduction of 2,2,6-trimethyl-2-cyclohexane-1,4-dione by the action of a yeast (F. Kienzle, H. Meyer, R. E. Minder and H. Thommen, Helv. Chim. Acta., 61, 2616 (1978)). This method, however, can only be applied to the synthesis of an enantiomorph of the (-)-isomer.